40345661 has 2 divisors, whose sum is σ = 40345662. Its totient is φ = 40345660.

The previous prime is 40345649. The next prime is 40345717. The reversal of 40345661 is 16654304.

It is a happy number.

40345661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 24940036 + 15405625 = 4994^2 + 3925^2 .

It is a cyclic number.

It is not a de Polignac number, because 40345661 - 2¹⁰ = 40344637 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40345621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20172830 + 20172831.

It is an arithmetic number, because the mean of its divisors is an integer number (20172831).

Almost surely, 2^40345661 is an apocalyptic number.

It is an amenable number.

40345661 is a deficient number, since it is larger than the sum of its proper divisors (1).

40345661 is an equidigital number, since it uses as much as digits as its factorization.

40345661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8640, while the sum is 29.

The square root of 40345661 is about 6351.8234389819. The cubic root of 40345661 is about 342.9774852269.

Adding to 40345661 its reverse (16654304), we get a palindrome (56999965).

It can be divided in two parts, 403 and 45661, that added together give a palindrome (46064).

The spelling of 40345661 in words is "forty million, three hundred forty-five thousand, six hundred sixty-one".